1. Field of the Invention
The present invention relates to an image determination apparatus, an image determination method, and a program for causing a computer to execute the image determination, and an image processing apparatus, an image processing method, and a program for causing a computer to execute the image processing.
2. Description of Related Art
Recently, along with the start of digital broadcasting, high-definition resolution (HD-resolution) image signals are transmitted from broadcasting stations or the like. However, image signals transmitted from the broadcasting stations or the like are not all HD-resolution image signals, but may in some cases contain pseudo HD-resolution image signals which are upconverted from the standard-definition resolution (SD-resolution) image signals used in the traditional analog broadcasting, into HD-resolution image signals.
For upconverting an SD-resolution image into an HD-resolution image, a side panel method, a top and bottom crop method, a stretch method, and the like are known.
Generally, a pseudo HD-resolution image upconverted from an SD-resolution image into an HD-resolution image is inferior in image quality to a pure HD-resolution image, and thus needs to enhance its outline by using, e.g., an image enhancer or the like.
Meanwhile, technologies are under development for determining whether or not an image signal represents an image obtained upconverted from an SD-resolution image into an HD-resolution image.
For example, Japanese Unexamined Patent Application Publication No. 2005-65195 discloses an image determination technology by detection of side panels. Furthermore, e.g., Japanese Unexamined Patent Application Publication No. 2005-26814 discloses another image determination technology that involves calculation of an average brightness in addition to detection of side panels.